[chbot] RS232 FILTER

[Marshland Engineering]

Hi Chaps

Thanks for the replies. Never thought of it before but the earthing is
probably the issue. I have full filters on the 3 phase mains input lines so
hopefully not coming from there.  

So ideally, an optically isolated 485 would be the best. The communications is
coming from a PC so I can get a USB to 485 plug. Now I need one on the  mill
side. Now power available there. 

Here is an option.

https://www.usconverters.com/usb-rs485-isolated-converter

Thanks Wallace.